一株犬细小病毒云南毒株生物学特性分析

为了解当前犬细小病毒云南地方毒株的生物学特性,本试验将疑似病犬粪便经处理后接种于F81细胞,逐日观察病毒致细胞病变效应(CPE),对能引起细胞出现CPE的培养物进行病毒粒子电镜观察和分子生物学检测;在此基础上,完成分离病毒的部分生物学特性分析。结果表明,分离物在F81细胞盲传3代后开始出现拉网,脱落,崩解和破碎等CPE现象;电镜下可见病毒粒子呈圆形或六边形,无囊膜,直径约为20 nm;PCR检测出现目的条带,序列分析结果显示该毒株序列和犬细小病毒参考毒株核酸同源性为98.8%~99.7%。该毒株在生物学特性上除具有一般犬细小病毒相关特性外,还表现出异步接毒可致F81细胞出现明显CPE及能凝集食蟹猴红细胞的特性。基于VP2基因序列分析显示分离株基因型为新CPV-2a型,部分有生物学意义位点发生突变,亲缘关系与国内参考毒株关系较远,而与韩国参考毒株亲缘关系较近。提示,本试验成功分离获得一株犬细小病毒云南地方流行毒株,命名为YNX20090901株。

Analysis of Biological Characteristics of a New Canine Parvovirus Yunnan Strain

To obtain local epidemic strains of canine parvovirus (CPV) in Yunnan and study the biological characteristics,faecal samples from dogs suspected with CPV were collected and used to viral isolation. The isolates were proceeded to cytopathic effect (CPE) observation on F81 cells. It shows that after the isolates blind passaged on F81 cells three times,the generations of the isolates appeared some CPE phenomenon. Electron microscope revealed the presence of circular or hexagonal virus particles of about 20 nm in diameter which are free of envelope and the results of PCR showed positive. The homology reaches 98.8% to 99.7% between the amplification sequence and the standard sequence for reference. Besides of the common characteristics of canine parvovirus,they also showed that asynchronous post-inoculation may lead to obvious CPE phenomenon on F81 cells and the characteristics of agglutinating with erythrocytes of Macaca fascicularis. According to the analysis of VP2,the genome of the isolate is a new CPV-2a and found to be distantly related to the standard strains for reference in China while a close related to the standard strains for reference in Korea. It is indicated that a local epidemic strain of CPV in Yunnan named YNX20090901 strain was successfully separated,and found the biological characteristics of the new strain.